Anchoring device and its implementation

ABSTRACT

Anchor ( 115 ) particularly useful for providing ligamentory support between two spaced locations in the body of a patient includes a base ( 153 ), a head ( 157 ) having a configuration to facilitate insertion of the head into the tissue and retention of the head in the tissue once inserted. The base is formed with an aperture ( 161 ) adapted to receive a length of a filamentary element ( 127 ) and permit slidable movement of the filamentary element through the aperture in one direction. Movement of the filamentary element in the opposite direction through the aperture is prevented by a locking element.

This invention, which claims the priority date of Australian PatentApplication 2002951024 filed Aug. 13, 2002; Australian PatentApplication 2002952128 filed Oct. 17, 2002; and; Australian PatentApplication 2003902559 filed May 23, 2003; relates to an anchor whichcan be used in surgical procedures on both humans and animals.

This invention relates to an anchor which can be used in surgicalprocedures on both humans and animals.

BACKGROUND ART

The invention has application to a wide variety of surgical proceduresand one such procedure relates to a method of resolving femaleincontinence, which involves insertion of a filament which is to befixed to the ligamentous tissue to either side of the vagina in order toreconstitute the ligamentary support for the urethra and/or vaginalwall. In the past such filaments have either been fixed to the pubicbone or alternatively the rectus abdominous muscle or left “tensionfree” in that muscle.

The inventor is the principal author of an article entitled “Role of thePelvic Floor in Bladder Neck Opening and Closure II: Vagina” whichappeared in the International Urogynecology Journal (1997) 8:69-73. Inthat article it was identified the “connective tissue laxity in thevagina or its supporting ligaments is the prime cause of symptoms ofstress, urgency and abnormal emptying”. As a result in the case of a laxvagina, at least some of the muscular activity which is applied tomaintain continence is taken up in resolving the vaginal laxity ratherthan control of the urethra. Therefore in rectifying the problem it isdesirable to establish a situation in which the relationship between theexisting muscular and ligamentory support can be reestablished

DISCLOSURE OF THE INVENTION

Accordingly in one aspect the invention resides in a method of providingligamentory like support between two spaced locations in the body of apatient wherein the locations comprise ligament and/or muscle tissuecomprising fixing an anchor in each location, connecting the anchors bya filamentary element, adjusting the tension of the filamentary elementbetween the locations to establish the desired spatial relationshipbetween the locations to provide at least a supplementary ligamentorysupport between the locations.

According to a preferred feature of the invention the locations compriseligament and/or muscle tissue.

According to a preferred feature of the invention the anchors areprovided with a retaining means adapted to be able to retain thefilamentary element in optimal tension between the anchors.

According to a preferred feature of the invention the retaining meansenables movement of the filamentary element through the anchor to enablethe length of the filamentary element between the locations to beshortened but to prevent movement of the filamentary element through theanchors to enable the length of the filamentary element between theapplications to be increased.

According to a further preferred feature of the invention thefilamentary element is not biodegradable over a period of time and isadapted to facilitate the growth of tissue between the locations toprovide said ligamentory support between the locations.

According to a preferred feature of the invention the anchor comprises ahead having a configuration facilitating insertion into the tissue andretention of the head in the tissue once inserted, the anchor furtherhaving a base which is intended to receive the filamentary element, saidmethod comprising inserting the head of the anchor into the tissue withthe base buried in the tissue.

According to a further preferred feature of the invention the head has abarbed configuration. According to a preferred feature of the inventionthe barbed configuration comprises a set of prongs extending in adivergent manner from the end of the head towards the base, said prongsbeing resiliently flexible along their length, said method comprisingcompressing the ends of the prongs towards each other prior to insertionof the head into the tissue, inserting the head into the tissue andreleasing the ends of the prongs once the head is located in the tissue.

According to a further preferred feature of the invention the anchor isassociated with a holder which is configured to retain the anchor withthe head directed outwardly from the holder, the method comprisinginstalling an anchor in the holder and placing the anchor in position inthe tissue by means of the holder, subsequently disengaging the holderfrom the anchor. According to a preferred feature of the invention thefilamentary element is installed in the anchor and the anchor isinstalled on the holder prior to insertion of the head into the tissue.According to a preferred feature of the invention the holder is adaptedto receive and support the prongs in their compressed state, said methodcomprising releasing the prongs from engagement with the holder when theanchor is in position.

According to a further preferred feature of the invention the holder isassociated with an insertion appliance, the insertion appliance having ashaft, one end of the shaft adapted to receive the holder, the other endof the shaft supporting the handle, an ejection means extending betweenthe handle and the one end and having a bearing member at one endadapted to bear upon an anchor when installed in the holder, the handleprovided with a manipulation member adapted to cause the bearing memberto bear on the anchor and cause the displacement of the anchor from theholder, said method comprising locating the holder at the one end of theshaft, installing an anchor into the holder, placing the anchor inposition in the tissue by manipulation of the appliance and on locationof the anchor in the tissue, activation of the manipulation means tocause displacement of the anchor from the holder.

According to a preferred feature of the invention the spaced locationscomprise the recto-vaginal ligaments or the arcus tendineus ligaments toeach side of the vagina and the method resides in the re-establishing ofthe fascial support for the vagina, said method comprising fixing saidanchors into the recto-vaginal ligaments or the arcus tendineusligaments respectively to each side of the vagina, applying thefilamentary element between the anchors and introducing the filamentaryelement into the fascial tissue such that with time it will becomeembodied with the fascia and optimally tensioning the filamentaryelement between the anchors.

According to a preferred feature of the invention the filamentaryelement is applied to at least one of the anchors prior to fixation.According to a preferred embodiment of the invention the filamentaryelement is applied to a pair of anchors at a spacing greater than thatdesired spatial relationship.

According to another aspect the invention resides in a tissue anchorformed of a material which is compatible for location in human and/oranimal muscle and/or ligament tissue, the anchor comprising a base and ahead, the head having a configuration to facilitate insertion of thehead into tissue and retention of the head in the tissue once inserted,the base formed with an aperture adapted to receive a length of afilamentary element and permit slidable movement of the filamentaryelement through the aperture in one direction but to restrict movementof the filamentary element through the aperture in the oppositedirection.

According to a preferred feature of the invention the aperture isassociated with a locking element positioned to extend across theaperture to define a space between the locking element and an opposededge of the aperture, said space being intended to receive thefilamentary element, the locking member having one face proximate theone direction and another face proximate the opposite direction, thelocking element intended to cooperate with the filamentary element whenin position in the space to restrict the movement of the filamentaryelement in the opposite direction and to enable movement of thefilamentary element in the one direction. According to a preferredfeature the edge of the locking element defining the space is formed toengage the surface of the filamentary element when filamentary elementis moved in the opposite direction. According to a preferred feature ofthe invention the edge is defined by a surface extending between thefaces of the locking member, the surface being inclined away from theopposed edge of the aperture in the opposite direction. According to apreferred feature of the invention the edge is formed with slots whichextend from the face proximate the one direction to at least anintermediate position across the surface. According to a preferredfeature of the invention the face of the locking member proximate theone direction is formed as a recess inwardly of the edge. According to apreferred feature the locking member is inclined with respect to thebase.

According to a preferred feature the space has a configurationsubstantially corresponding to the cross section of the filamentaryelement. According to a preferred feature of the invention the space hasa configuration corresponding to the cross sectional configuration ofthe filamentary element when under longitudinal tension. According to apreferred feature of the invention the space has a part annularconfiguration. According to a preferred feature of the invention theopposed edge of the locking element which is remote from the head has aconvex arcuate configuration. According to a preferred feature of theinvention the space is located substantially centrally across thecentral longitudinal axis of the anchor.

According to a preferred feature of the invention the head has a barbedconfiguration. According to a preferred feature of the invention thebarbed configuration of the head is defined by a set of prongs, saidprongs being located in substantially equi-distant spacing around thecentral axis of the head, said prongs being divergent away from the endof the head in the direction of base.

According to a preferred feature of the invention the prongs are of atapered configuration. According to a preferred feature of the inventionthe outer end of the prongs are pointed. According to a preferredfeature of the invention the prongs are resiliently flexible along theirlength.

According to a further aspect the invention resides in a holder adaptedto support the anchor as described above comprising a socket configuredto clampingly receive the base, the socket being configured to allowaccess to the aperture, the clamping engagement between the holder andthe base being such that on relative movement between the holder and theanchor the anchor is able to be disengaged from the holder.

According to a preferred feature of the invention the base has asubstantially laminar-like configuration comprising two opposedsubstantially parallel faces.

According to a preferred feature of the invention the socket comprises apair of spaced elements which receive opposed sides of the base with theaperture between the spaced elements.

According to a preferred feature of the invention the socket is definedby a set of boss elements which are configured to receive the free endsof the prongs of the anchor when compressed radially with respect to thecentral axis of the anchor.

According to a further aspect the invention resides in an insertionappliance comprising a shaft adapted to accommodate the holder asdescribed above at one end, the other end of the shaft supporting ahandle, an ejection means extending between the one end and the handle,a bearing member provided at the one end and a manipulation meansprovided adjacent the handle whereby on an anchor being installed in theholder and on activation of the manipulation means the bearing memberwill bear upon the anchor to move the anchor from engagement with theholder.

According to a preferred embodiment a holder of the form described abovehaving an anchor of the form described above applied thereto areprovided as a single element.

According to a preferred embodiment an insertion appliance of the formdescribed above supporting a holder of the form described above havingan anchor of the form described above applied thereto are provided as asingle element.

The invention will be more fully understood in the light of thefollowing description of several specific embodiments

BRIEF DESCRIPTION OF THE DRAWINGS

The description is made with reference to the accompanying drawings ofwhich:

FIG. 1 is a schematic view of the posterior vaginal wall repairaccording to the first embodiment.

FIG. 2 is an isometric view of an anchor according to the secondembodiment;

FIG. 3 is a sectional isometric view of the anchor of the secondembodiment;

FIG. 4 is a side elevation of an insertion tool intended for use withthe anchor of the second embodiment;

FIG. 5 is an enlarged isometric view of the end of the insertion toolsupporting an anchor according to the second embodiment.

FIG. 6 is an isometric view of an anchor according to the thirdembodiment;

FIG. 7 is a sectional side elevation of an anchor according to the thirdembodiment;

FIG. 8 is a side elevation of an anchor according to the thirdembodiment;

FIG. 9 is a sectional elevation of an anchor according to the thirdembodiment illustrating engagement between the anchor and a filamentaryelement;

FIG. 10 is an isometric view of an anchor according to the thirdembodiment engaged with a filamentary element;

FIG. 11 is an isometric view of an anchor according to the thirdembodiment in engagement with a cradle like support and alsoillustrating the anchor out of engagement with the cradle like support;

FIG. 12 is a sectional side elevation of an insertion applianceaccording to the third embodiment;

FIG. 13 is an isometric view of anchor and a holder according to thethird embodiment;

FIG. 14 is an isometric view of anchor according to the fourthembodiment;

FIG. 15 is an end elevation and two side elevation of a cradle likesupport according to the fourth embodiment;

FIG. 16 are isometric views of the cradle like support according to thefourth embodiment;

FIG. 17 is a side elevation of an insertion appliance according to thefourth embodiment;

FIG. 18 is an illustration of a pair of holder like supports eachaccommodating an anchor which in turn is received on a filamentaryelement;

FIG. 19 is illustrative of the initial step involved in operation of theanchor for insertion;

FIG. 20 is an illustrative view of the insertion appliance subsequent torelease of the first anchor;

FIG. 21 is a schematic view of an insertion applicant applied to thesecond anchor;

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

The method according to the first embodiment comprises utilisation of ananchor of the form described below as the second and third embodiments.The anchor provides a means of attaching a filament into muscle and/orligamentary tissue. The anchor has a head which is able to be embeddedinto the tissue whereby once it is so embedded the anchor is retained inposition. In addition the anchor has an attachment means which is ableto receive and support a filament whereby the filament can slide throughthe attachment means in one direction but is restrained from slidablemovement in the opposite direction.

It is the purpose of the procedure according to the embodiment toincorporate into the fascial tissue, which is located above and belowthe vaginal wall, a supporting filamentary element which is supported ateither end from either the recto-vaginal ligaments or the arcustendineus (A.T.F.P.) ligaments located to each side of the vagina.

As shown in schematically at FIG. 1 the procedure according to the firstembodiment involves forming a longitudinal incision in the anteriorand/or posterior vaginal wall. This results in the creation of a pair offlaps 11 of fascial tissue to each side of the longitudinal incision.One or more lengths of filamentary element 13 are then fixed to each ofeither the recto-vaginal ligaments or the arcus tendineus (A.T.F.P.)ligaments which are located to each side of the vagina. The fixing ofeach length of filament is effected through a pair of anchors 15 of theform described below which receive the ends of the length of filamentwhereby because of the nature of the attachment means the spacingbetween the anchors 15 on the length of filamentary element 13 can bereduced by causing the filamentary element to be drawn through theattachment means of the anchor. The spacing between the anchors on thefilamentary element cannot be increased. The anchors 15 on each lengthof filamentary element 13 are embedded into the recto-vaginal ligamentsin opposed relationship to each side of the vagina. Once the anchors 15are attached, the nature of the attachment means of the anchors enablesthe length of the filament 13 between the ligaments to be reduced and tointroduce a degree of tension into the filamentary element between theligaments. The flaps 11 of fascial tissue are then resutured into place.With the healing of the incisions the filamentary element becomesembodied into the fascial tissue on the anterior and posterior sides ofthe vaginal walls to provide reinforcement and support for that fascialtissue.

The tensioning of the filamentary element on its location in positionbetween the recto-vaginal ligaments or the arcus tendineus (A.T.F.P.)ligaments enables the filamentary element to be precisely andsufficiently tightened to bring the fascia towards the mid-line and inso doing serves to repair any hernia. This serves to restore support forthe vaginal wall and to facilitate the desired transmission of themuscle contraction to effect opening and closure of the urethra and anuswithout the muscle having initially to take up the laxity thatpreviously existed in the connection between the fascial tissue and therecto-vaginal ligaments.

Each of the remaining embodiments are directed to an anchor which can beutilised in association with a filamentary element to enable the fixingand location of the filamentary element into a patient as describedabove in relation to the first embodiment.

The filamentary element which is used in the first embodiment and withwhich the second and third embodiments are used comprises a tape whichis formed of a knitted or woven material where the material once locatedin the body will facilitate the growth of scar-like tissue upon it

The anchor 15 according to the second embodiment is shown at FIGS. 2 to5. The anchor is formed integrally of a suitable plastics material whichmay be biodegradable and comprises a base 53, a stem 55 which extendsfrom the base 53 and a head 57 which is supported in spaced relationfrom the base 53 by the stem 55. The base is of a generally laminarconfiguration wherein the major faces of the base are substantiallyplanar and parallel to the central axis of the stem 55. The base isformed with an aperture 61 which extends between the faces and which isassociated with a locking member 63 which extends from the side of theaperture proximate the head 57 to terminate closely adjacent the otherside of the aperture. The free end of the locking member has a convexarcuate configuration to cooperate with the other side of the apertureto define a part annular space. The spacing between the other side ofthe aperture and the free end of locking member approximatelycorresponds with the thickness of the filamentary element with which theanchor is to be used, when the filamentary element is tensioned.

The junction of the locking member with the one side of the aperture issuch that the locking member can flex laterally out of the plane ofaperture in one direction but is resistant to movement out of the planeaperture in the other direction. This selective flexing of the lockingmember is achieved by forming the one face of the locking member 63which faces the one direction with a recess 65 which has a boundaryadjacent the junction. In addition the edge of the locking member 63 inthe region adjacent the space is formed with a set of spaced slots 67which extend from the one face partially across the end face of thelocking member and which define a set of teeth at that edge. In additionthe end face 69 of the locking member is divergent away from the otherface of the aperture in the opposite direction. The function of theselective flexing of the locking member 63 and the configuration of theteeth is to permit the filamentary element to be able to be pulledthrough the space between the locking member and the one side of theaperture in the one direction and to prevent movement of the filamentaryelement through the same space in the opposite direction. The engagementof the filamentary element by the locking member when the filamentaryelement is moving in the opposite direction is enhanced by the partannular configuration of the space through which the filamentarymaterial is required to pass which causes the filamentary element tofurrow in its passage through the space and thus engage with the freeedge of the locking member. The divergent nature of the end face 69serves to guide and enable the movement of the filamentary element inthe one direction.

The head 57 of the second embodiment comprises an outer portion 71 whichhas a pointed conical configuration. In addition the head 57 has abarbed configuration which is provided by a set of prongs 72 whichextend rearwardly from the outer portion 71 in a divergent relationshipto each other. The arms 69 are spaced angularly equi-distant around thecentral axis of the stem 55 and each of the arms are of a generallytapered configuration with their outer ends being more convergent thanthe main portion of each prong 72. Because of the nature of the plasticsmaterial of which the anchor is formed the prongs are capable ofresilient flexing along their length and at their junction with thestem.

In use the anchor 15 of the second embodiment is intended to be attachedto a length of the filamentary element (not shown) and the filamentaryelement is inserted into the body of a patient by utilisation of aninsertion appliance 70 which is illustrated at FIGS. 4 and 5. Theinsertion appliance comprises a tubular body 73 which is provided at oneend with a handle 75 and at the other end with a cradle-like support 77.The cradle-like support 77 is configured to receive the base of theanchor 15 of the second embodiment and support the anchor as shown atFIGS. 4 and 5 with the head 71 extending axially away from the end ofthe appliance. The internal bore of the insertion tube slidably supportsa pushrod 79 which extends from the one end of the tubular body and isprovided with an enlarged head 81 at its outer end The other end of thepushrod is received through a passageway through the cradle-like support77 to terminate closely adjacent the anchor when supported in thecradle-like support 77. A suitable biasing means is provided between thetubular body 73 and the pushrod 79 to bias the pushrod to its outermostposition with respect to the tubular body 73.

In use the anchor 15 is located in the cradle-like support 77 of theinsertion tube and the filamentary element (not shown) is initiallypassed through the aperture of the anchor. The insertion tube 73 is theninserted into the body cavity through an opening in the body wall suchthat the free end of the insertion tube with the anchor located thereonis located against the surface of a layer of muscle tissue. With theapplication of an inward axial force on the enlarged head 81 of thepushrod 79, the anchor 15 is caused pass into the muscular tissue tobecome lodged therein. Because of the pointed configuration of the outerportion 71 of the head, the anchor 15 will move readily into engagementwith the tissue, however because of the divergent nature of the arms 25,dislodgement of the anchor from the tissue is restricted. Once theanchor is firmly in position pressure is applied to the enlarged head 81of the pushrod to displace the anchor from the cradle-like support andthen the insertion appliance 70 can be removed from the body to leavethe anchor and filamentary element 27 in place. A second anchor isengaged with the filamentary element at its other end and the secondanchor is then fixed to another location in a similar manner using theinsertion appliance. Because the filamentary element is only capable ofmovement through the aperture of the anchors in one direction, thelength of the filamentary element supported between the anchors can bereduced, to reduce the spacing between the locations and can betensioned.

Where the filamentary element is used to provide a sling-like supportbetween two anchors supported in the recto-vaginal ligaments asdescribed in relation to the first embodiment the tensioning applied tothe filamentary element is such as to restore the normal tension whichis expected at the at site to enable the muscular action which isavailable to be used to control the urethra.

The anchor 115 according to the third embodiment is shown at FIGS. 6 to13. The anchor is formed integrally of a suitable plastics materialwhich may be biodegradable and comprises a base 153, a stem 155 whichextends from the base 153 and a head 157 which is supported in spacedrelation from the base 153 by the stem 155 (at a reduced spacingcompared to the second embodiment). The base is of a generally laminarconfiguration wherein the major faces of the base are substantiallyplanar and parallel to the central axis of the stem 155. The base isformed with an aperture 161 which extends between the faces and which isassociated with a locking member 163 which extends from the side of theaperture proximate the head 157 to terminate closely adjacent the otherside of the aperture. The locking member 163 is substantially planar andis inclined with respect to the central transverse plane of the basefrom one face to the other face. The free edge of the locking member hasa convex arcuate configuration to cooperate with the other side of theaperture to define a part annular space. The spacing between the otherside of the aperture and the free edge of locking member approximatelycorresponds with the thickness of the filamentary element with which theanchor is to be used when the filamentary element is tensioned.

The locking member is of a reduced thickness compared to the thicknessof the base and as a result the locking member can flex within theaperture. In addition the edge of the locking member 163 in the regionadjacent the space is formed with a set of angularly spaced slots 167which extend from the one face partially across the end face 169 of thelocking member to define a set of teeth at that edge. In addition theend face 169 of the locking member is divergent away from the other faceof the aperture in the opposite direction. The flexing of the lockingmember 163, the configuration of the teeth 167 and the configuration ofthe end face 169 permit the filamentary element 127 to be able to bepulled through the space between the locking member and the one side ofthe aperture in the one direction with substantially littleinterference. The divergent nature of the end face 169 serves to guideand enable the movement of the filamentary element in the one direction.In addition when the filamentary element 127 is moving in the onedirection it is anticipated that it will be in a state of tension and asa result it is expected that the locking member will not interfere withthe filamentary element 127 when it is moving in the one direction sincethe dimensions of the space will correspond with the cross section ofthe tensioned filamentary element 127 passing through it. However theflexing of the locking member 163, the configuration of the teeth 167and the configuration of the end face 169 also serve to, preventmovement of the filamentary element 127 through the same space in theopposite direction. The engagement of the filamentary element 127 by thelocking member when the filamentary element 127 is moving in theopposite direction is enhanced by the part annular configuration of thespace through which the filamentary element 127 is required to passwhich causes the filamentary element 127 to furrow in its passagethrough the space and thus engage with the free edge of the lockingmember as shown at FIGS. 9 and 10. When the filamentary element 127 iscaused to move in the opposite direction the portion of the elementapproaching the aperture will generally not be in tension and thiscondition of the element together with the configuration of the space,serves to further enhance the interference that the locking membercreates for movement of the filamentary element. In addition in thelight of the inclined orientation of the locking member across theaperture, on movement of the filamentary element through the space inthe opposite direction the interference therebetween will cause the freeend of the locking member to move resiliently towards the opposite edgeof the aperture and clampingly engage the filamentary elementtherebetween. Therefore the relationship between the locking member andthe aperture serves to positively prevent the filamentary element 127from movement in the opposite direction through the space.

The head 157 of the third embodiment comprises an outer portion 171which has a pointed conical configuration. In addition the head 157 hasa barbed configuration which is provided by a set of prongs 172 whichextend rearwardly from the outer portion 171 in a divergent relationshipto each other. The arms 169 are spaced angularly equidistant around thecentral axis of the stem 155 and each of the arms are of a generallytapered configuration with their outer ends being more convergent thanthe main portion of each prong 172. Because of the nature of theplastics material of which the anchor is formed the prongs are capableof resilient flexing along their length and at their junction with thestem.

In use the anchor 115 of the third embodiment is intended to be attachedto a length of the filamentary element as shown at FIGS. 9 and 10 andthe filamentary element is inserted into the body of a patient byutilisation of an insertion appliance 170 which is illustrated at FIG.12. The insertion appliance comprises a tubular body 173 which isprovided at one end with a handle 175 and at the other end is adapted toreceive a cradle-like support 177. The cradle-like support 177 isconfigured to receive the base of the anchor 115 of the third embodimentand support the anchor as shown at FIGS. 6 to 10 with the head 171extending axially away from the end of the appliance. The cradle-likesupport is described in greater detail below. The internal bore of theinsertion tube slidably supports a pushrod 179 which extends from theone end of the tubular body into the interior of the handle 175. Theother end of the pushrod is received through a passageway through thecradle-like support 177 to terminate closely adjacent the anchor whensupported in the cradle-like support 177. A suitable biasing means isprovided between the tubular body 173 and the pushrod 179 to bias thepushrod towards the handle. The handle slidably receives a rod-shapedplunger 183 and the outer end of the pushrod 179 bears on the plunger18. The portion of the surface of the plunger which receives the pushrodis profiled with a notched portion 185 which receives the outer end ofthe pushrod when in its retracted position and with an increaseddiameter portion 187 which will receive the outer end of the pushrodwhen the plunger is pushed axially inwardly into the handle to cause thepushrod to move to its extended position. When the pushrod is at itsextended position it will bear upon anchor 115 supported on thecradle-like support 177 to force the anchor out of engagement with thecradle-like support 177.

As shown at FIG. 11 the cradle-like support comprises a central spigot187 which is intended to be received in the end of the tubular body 173and is configured to be frictionally engaged in the end. The outer endof the spigot supports cradle 189 which is shaped to support the base153 of an anchor at the sides. The cradle is recessed to provide freeaccess to the aperture 161. In addition the sides of the recess areconfigured at their outer ends to receive and support the free ends ofthe prongs 172 when compressed radially relative to each other as shownat FIG. 11. The cradle-like support is formed with a central passagewhich receives the pushrod 179 of the insertion appliance whereby whenthe pushrod is at its extended position it bears upon the base of theanchor to force it out of engagement with the cradle 189. When theanchor is free of the cradle-like support the free ends of the prongsare able to expand radially.

To locate the anchor in position on the cradle-like support, a holder191 of the form shown at FIG. 13 is used. The holder comprises bodyhaving a grip 193 at one end and an anchor support 195 at the other end.The grip 193 comprises a pair of opposed tabs 197 which are dimensionedand spaced from each other to be able to be engaged between a finger andthumb of the operator. The anchor support comprises a cross-like recess199 which is configured to receive the head of the anchor, including theprongs and in so doing to radially compress the free ends of the prongsin order that they can be received in the cradle 189 of the cradle-likesupport.

In use the head of an anchor 115 is located in the recess of the holderand is then transferred to the cradle-like support 177 to be supportedtherein. This location and transfer of the anchor can be effected usingthe holder and without manually handling the anchor. The anchorpreloaded with the filamentary element is supported in the cradle-likesupport. The insertion tube 173 is then inserted into the body cavity ofthe patient through an opening in the body wall such that the free endof the insertion tube with the anchor located thereon is located againstthe surface of a layer of muscle tissue. On application of additionalforce the head of the anchor as well as a portion of the cradle-likesupport is introduced into the muscle tissue. With the depression of theplunger of the insertion appliance, the pushrod 179 forces the anchorout of engagement with the cradle-like support to be received in themuscle tissue and to become lodged therein. The radial expansion of thefree ends of the prongs when free of the cradle further serve to ensureretention of the anchor in the tissue. Because of the pointedconfiguration of the outer portion 171 of the head, the anchor 115 willmove readily into engagement with the tissue, however because of thedivergent nature of the prongs 125, dislodgement of the anchor from thetissue is restricted. The retention of the free ends of the prongs inthe cradle enables the operator some degree of freedom in locating theanchor and the prongs are only released when the operator is satisfiedwith the location of the anchor. Once the anchor is firmly in positionthe insertion appliance 171 can be removed from the body to leave theanchor and filamentary element 127 in place. A second anchor at theother end of the filamentary element is then fixed to another locationin a similar manner using the insertion appliance. Because thefilamentary element is only capable of movement through the aperture ofthe anchors in one direction, the length of the filamentary elementsupported between the anchors can be reduced, to reduce the spacingbetween the locations and can be tensioned.

Where the filamentary element is used to provide a sling-like supportbetween two anchors supported in the recto-vaginal ligaments asdescribed in relation to the first embodiment the tensioning applied tothe filamentary element is such as to restore the normal tension whichis expected at the at site enable the muscular action which is availableto be used to control the urethra.

According to a fourth embodiment as illustrated at FIGS. 14 to 21 ananchor 215 of the form as shown at FIG. 14 and which generallycorresponds with an anchor according to the third embodiment is appliedto a cradle-like support 277. As illustrated in FIGS. 15 and 16 thecradle-like support 277 is formed as a tubular element which isreceivable over the outer end of insertion tool 270 and is formed at oneend with a cradle like portion which will support and engage the anchor215 in a similar manner to that described in relation to the thirdembodiment and as shown in the accompanying drawings. The configurationof the insertion appliance 270 is of the same form as that of the thirdembodiment. The tubular portion of the cradle-like support is formedtowards its other end to be of a bifurcated configuration to allow forresilient flexing between the bifurcated portions of the tubular portionso defined when other end of the cradle-like support is applied over theouter end of the insertion appliance in order that they clampinglyengage the outer surface of the tubular portion at 273 of the insertionappliance 270. If desired suitable detents may be provided in the wallof the tubular portion 273 to retain the cradle-like support in positionon the end of the insertion appliance.

In addition the insertion appliance 270 is provided with a collar 292which is slidable on the tubular portion of the insertion appliance 270.The collar 292 is provided with a pair of diametrically opposed prongs294 which will engage in the slots between the bifurcations of thecradle-like support and with appropriate axial movement of the collar onthe tubular member will cause separation between the bifurcations tofacilitate removal of the cradle-like support from engagement with theinsertion appliance.

In use the cradle-like support 277 and the anchor 215 is provided as asingle item and it is intended that a pair of composite items beprovided on a length of filamentary element 227 as a pre-packagedcomposite item whereby the anchors 215 are sequentially installed usingan insertion tool in a manner as illustrated at FIGS. 20-21.

In an alternative application of the anchors according to the second,third and fourth embodiments they are used to directly shorten astretched ligament or fascial tissue by inserting a pair of anchors intoa ligament at spaced intervals along the ligament and shortening theligament or fascial tissue by tensioning the filamentary element betweenthe anchors.

Throughout the specification, unless the context requires otherwise, theword “comprise” or variations such as “comprises” or “comprising”, willbe understood to imply the inclusion of a stated integer or group ofintegers but not the exclusion of any other integer or group ofintegers.

It should be appreciated that the scope of the invention need not belimited to the particular scope of the embodiment described above and inparticular is not restricted to the particular example of application ofthe embodiment described above.

The invention claimed is:
 1. A tissue anchor formed of a material whichis compatible for location in human and/or animal muscle and/or ligamenttissue and/or tissue, the anchor comprising: a base and a head, the headincluding a plurality of tapered prongs that form a barbed configurationto facilitate insertion of the head into the tissue and retention of theanchor following insertion of the head in the tissue, the base includingan aperture having a longitudinal length between a first side and asecond side and a locking element, said locking element extending fromsaid first side of the aperture to terminate at a free end closelyadjacent to said second side of the aperture to define a space betweenthe free end of the locking element and the second side of the aperturefor receiving a filamentary element, the locking element arranged toflex in a first direction out of the plane of the aperture and beresistant to movement in a second direction out of the plane of theaperture, the locking element having a first face facing the firstdirection and a second face facing the second direction, the lockingelement further including a set of teeth arranged to engage with thefilamentary element when it is pulled in the second direction throughthe space, the set of teeth are defined by spaced slots extending fromthe first face to the second face, the set of teeth and flexure of thelocking element thereby permitting the filamentary element to be pulledin the first direction through the space whilst preventing thefilamentary element from being pulled in the second direction throughthe space, wherein the free end of the locking element has a convexarcuate configuration and the space is annular.
 2. A tissue anchor asclaimed in claim 1 wherein the space has a configuration substantiallycorresponding to the cross section of the filamentary element.
 3. Atissue anchor as claimed in claim 2 wherein the space has aconfiguration corresponding to the cross sectional configuration of thefilamentary element when under longitudinal tension.
 4. A tissue anchoras claimed in claim 1 wherein the space is located substantiallycentrally across the central lonaitudinal axis of the anchor.
 5. Atissue anchor as claimed in claim 1 wherein the locking member isinclined with respect to the base.
 6. A tissue anchor as claimed inclaim 1 wherein the prongs are located in substantially equidistantspacing around the central axis of the head, and the prongs diverge awayfrom the end of the head in the direction of the base.
 7. A tissueanchor as claimed in claim 1 wherein the outer end of the prongs arepointed.
 8. A tissue anchor as claimed in claim 1 wherein the prongs areresiliently flexible along their length.
 9. A tissue anchor as claimedin claim 1 wherein the locking element forms a flexible junction withthe aperture such that movement of the locking element in said onedirection increases the space between the second edge of the apertureand the locking element, and movement of the locking element in saidopposite direction acts to decrease the space between the second edge ofthe aperture and the locking element.
 10. A tissue anchor as claimed inclaim 1, wherein the head is formed with a pointed tip.
 11. A tissueanchor as claimed in claim 1, wherein said prongs extend radiallybackward from said head.
 12. A tissue anchor according to claim 1wherein the free end of the locking element has an end face thatdiverges away from the second side of the aperture towards the seconddirection.
 13. A tissue anchor according to claim 1 wherein theconfiguration of the space between the free end of the locking elementand the second side of the aperture causes the filamentary element tofurrow in its passage through the space so as to engage with the freeend of the locking element when it is pulled in the second directionthrough the space.
 14. A tissue anchor according to claim 1 wherein thefilamentary element is a woven or knitted tape.
 15. A tissue anchoraccording to claim 1 wherein the spaced slots are formed in an edge ofthe locking element.
 16. A tissue anchor according to claim 1 includingfour tapered prongs.
 17. A tissue anchor according to claim 1 whereinthe aperture is located in the base distal of the tapered prongs.
 18. Atissue anchor according to claim 1 wherein said base is attached to saidhead.
 19. A tissue anchor according to claim 1 wherein said lockingmember includes a front surface disposed at an acute angle with respectto said aperture and said free face is defined by an edge surfacedisposed at an acute angle with respect to said front surface.
 20. Andbe resistant to movement in a second direction out of plane of theaperture, the locking element having a first face facing the firstdirection and a second face facing the second direction, the lockingelement including a set of teeth arranged to engage with the filamentaryelement when it is pulled in the second direction through the space, theset of teeth are defined by spaced slots extending from the first faceto the second face, the set of teeth and flexure of the locking elementpermitting the filamentary element to be pulled in the first directionthrough the space whilst preventing the filamentary element from beingpulled in the second direction through the space, wherein the free endof the locking element has a convex arcuate configuration and the spaceis annular.
 21. The tissue anchor of claim 20 wherein said lockingelement is integral with said base.
 22. The tissue anchor of claim 20wherein said locking element is attached to and integral with said firstside.